UNIX — универсальная среда программирования

Керниган Брайан Уилсон

}

yyerror(s)

 char *s;

{

 warning(s, (char *)0);

}

execerror(s, t) /* recover from run-time error */

 char *s, *t;

{

 warning(s, t);

 longjmp(begin, 0);

}

fpecatch /* catch floating point exceptions */

{

 execerror("floating point exception", (char*)0);

}

warning(s, t)

 char *s, *t;

{

 fprintf(stderr, "%s: %s", progname, s);

 if (t && *t)

fprintf(stderr, " %s", t);

 fprintf(stderr, " near line %d\n", lineno);

 while (c != '\n' &&

с != EOF)

с = getchar; /* flush rest of input line */

}

3.5.4

init.c

#include "hoc.h"

#include "y.tab.h"

#include <math.h>

extern double Log, Log10, Exp, Sqrt, integer;

static struct { /* Constants */

 char *name;

 double eval;

} consts[] = {

 "PI", 3.14159265358979323846,

 "E", 2.71828182845904523536,

 "GAMMA", 0.57721566490153286060, /* Euler */

 "DEG", 57.29577951308232087680, /* deg/radian */

 "PHI", 1.61803398874989484820, /* golden ratio */

 0, 0

};

static struct { /* Built-ins */

 char *name;

 double (*func);

} builtins [] = {

 "sin", sin,

 "cos", cos,

 "atan", atan,

 "log", Log, /* checks argument */

 "log10", Log10, /* checks argument */

 "exp", Exp, /* checks argument */

 "sqrt", Sqrt, /* checks argument */

 "int", integer,

 "abs", fabs,

 0, 0

};

init /* install constants and built-ins in table */

{

 int i;

 Symbol *s;

 for (i = 0; consts[i].name; i++)

install(consts[i].name, VAR, consts[i].eval);

 for (i = 0; builtins[i].name; i++) {

s = install(builtins[i].name, BLTIN, 0.0);

s->u.ptr = builtins[i].func;

 }

}

3.5.5.

makefile

YFLAGS = -d

OBJS = hoc.o code.o init.o math.o symbol.o

hoc4: $(OBJS)

cc $(OBJS) -lm -o hoc4

hoc.o code.o init.o symbol.o: hoc.h

code.o init.o symbol.o: x.tab.h

x.tab.h: y.tab.h

– cmp -s x.tab.h y.tab.h || cp y.tab.h x.tab.h

pr: hoc.y hoc.h code.c init.c math.c symbol.c

@pr $?

@touch pr

clean:

rm -f $(OBJS) [xy].tab.[ch]

3.5.6.

math.c

#include <math.h>

#include <errno.h>

extern int errno;

double errcheck;

double Log(x)

 double x;

{

 return errcheck(log(x), "log");

}

double Log10(x)

 double x;

{

 return errcheck(log10(x), "log10");

}

double Sqrt(x)

 double x;

{

 return errcheck(sqrt(x), "sqrt");

}

double Exp(x)

 double x;

{

 return errcheck(exp(x), "exp");

}

double Pow(x, y)

 double x, y;

{